The percentage of the world population suffering from morbid obesity is steadily increasing. Severely obese persons are susceptible to increased risk of heart disease, stroke, diabetes, pulmonary disease, and accidents. Because of the effect of morbid obesity to the life of the patient, methods of treating morbid obesity are being researched.
Numerous non-operative therapies for morbid obesity have been tried with virtually no permanent success. Dietary counseling, behavior modification, wiring a patient's jaws shut, and pharmacologic methods have all been tried, and, though temporarily effective, have failed to correct the condition. Further, introducing an object into the stomach, such as an esophago-gastric balloon, to fill the stomach have also been used to treat the condition; however, such approaches tend to cause irritation to the stomach and are not effective long-term.
Surgical treatments of morbid obesity have been increasingly used with greater success. These approaches may be generalized as those that reduce the effective size of the stomach, limiting the amount of food intake, and those that create malabsorption of the food that is eaten. For instance, some patients benefit from adjustable gastric bands (AGB) that are advantageously laparoscopically placed about the stomach to form a stoma of a desired size that allows food to fill an upper portion of the stomach, causing a feeling of satiety. To allow adjustment of the size of the stoma after implantation, a fluid conduit communicates between an inwardly presented fluid bladder of the AGB to a fluid injection port subcutaneously placed in front of the patient's sternum. A syringe needle may then inject or withdraw fluid as desired to adjust the AGB.
Although an effective approach to obesity for some, other patients may find the lifestyle changes undesirable, necessitated by the restricted amount of food intake. In addition, the medical condition of the patient may suggest the need for a more permanent solution. To that end, surgical approaches have been used to alter the portions of the stomach and/or small intestine available for digesting food. Current methods of performing a laparoscopic anastomosis for a gastric bypass include stapling, suturing, and placing biofragmentable rings, each having significant challenges. For example, suturing is time consuming, as well as technique and dexterity dependent. Stapling requires placement of an anvil, which is a large device that may not be introduced through a trocar port. Introducing the port through a laparotomy presents an increased incidence of wound site infection associated with intralumenal content being dragged to the laparotomy entry site.
As an example of the latter approach, U.S. Pat. No. 6,543,456 discloses a method for gastric bypass surgery that includes the insertion of proximal and distal anastomosis members (e.g., anvils) transorally with grasping forceps. The stomach and the small intestine are transected endoscopically by a surgical severing and stapling instrument to create a gastric pouch, a drainage loop, and a Roux limb. An endoscopically inserted circular stapler attaches to the distal anastomosis member to join the drainage loop to a distal portion of the intestine, and the circular stapler attaches to the proximal anastomosis member to join the Roux limb to the gastric pouch. Thereafter, the anastomosis members are removed to create an orifice between joined portions of the stomach and intestine. This method reduces the number of laparoscopic ports, avoids a laparoscopic insertion of an anastomosis instrument (e.g., circular stapler) into an enlarged sugical port, and eliminates the need for an enterotomy and an enterotomy closure.
While methods such as those described are a marked improvement over generally known gastric bypass and similar surgical treatments for morbid obesity, it would be desirable to achieve a gastric bypass with yet fewer procedural steps and fewer laparoscopic insertions. Such an approach is described in U.S. Pat. Appl. Publ. No. U.S. 2003/0032967 to Park et al., wherein gastrointestinal or enteric (including biliary) anastomosis is achieved by insertion of a sheath that perforates the walls of two tissue passages, such as the stomach and small intestine. A three-dimensional woven tube of wire having a thermal shape memory effect (SME) (“nitinol Park device”) is presented by a cannula of the sheath on both sides of the openings. Deployment of the woven tube causes the outer loops or ends of the tube to fold or loop back to hold the luminal interface of the anastomosis site in apposition (close?). Thereby, the need for a mechanical compression component in a delivery system is reduced or avoided, reducing the size and complexity of the delivery device.
While the nitinol Park device is an advancement in the treatment of morbid obesity, it is believed that further improvements would be desirable. The Park device is a woven tube, or stent, that is purported to be a self-actuating anastomotic ring. However, the disclosed stent performs poorly in actuating or transforming from its stressed cylindrical state to its relaxed clamping state. Often, the stent remains stuck in the cylindrical shape after deployment, perhaps due to irregularities in undulations of its woven design that create friction. One particular difficulty of known SME anastomotic rings are that they are designed to move from a generally cylindrical shape to a hollow rivet shape (“ring shape”) by having wires that form the device move across one another. In particular, wires must move within a nodal point (i.e., an indentation or valley) created by the wire bend and must climb back out of the indentation. In some instances, the device fails to fully actuate on its own due to these sources of friction.
Consequently, there is a general need for an approach to creating an anastomosis for surgical procedures (e.g., gastro-jejeunostomies, etc.) that may be performed with a minimum number of transcutaneous punctures, which allows for the anastomosis procedure to potentially be performed on an out-patient basis. There is a further need for an anastomosis approach, which provides an anastomosis device that may fully and accurately deploy at an anastomotic site between multiple lumens.